1. Field of the Invention
The present invention relates to a white light-emitting device using a fluorescent fiber, and more particularly to a white light-emitting device, using a fluorescent fiber, which is suitable for being used as various kinds of a light source for a backlight for a liquid crystal television, and a light source including a neon tube.
2. Description of Related Art
In recent years, a light-emitting device using a semiconductor light-emitting element such as a light-emitting diode (LED) element or a light amplification by stimulated emission of radiation (LASER) element has been widely utilized as various kinds of a light source because it is advantageous in miniaturization, an excellent power efficiency, and a long life as compared with the case of an incandescent lamp.
Heretofore, a light source including a semiconductor light-emitting element for emitting an excitation light, a wavelength-converting member containing therein a phosphor material for emitting wavelength conversion lights by receiving the excitation light emitted from the semiconductor light-emitting element, and an optical fiber for guiding the excitation light to the wavelength-converting member has been known as this sort of a light source. This light source, for example, is disclosed in the Japanese Patent Kokai No. 2005-205195.
In such a light source, when the excitation light emitted from the semiconductor light-emitting element reaches the wavelength-converting member through the optical fiber, the phosphor material receives a part of the excitation light to make the wavelength conversion, thereby emitting wavelength conversion lights each having a predetermined wavelength range within the wavelength-converting member. The resulting wavelength conversion lights and the excitation light emitted from the semiconductor light-emitting element are then optically multiplexed to be radiated in the form of an illuminating light to the outside.
However, in the case of the light source disclosed in the Japanese Patent Kokai No. 2005-205195, the wavelength-converting member is connected to a light emission side end face of the optical fiber. As a result, there is encountered such a problem that an optical coupling loss is generated between the optical fiber and the wavelength-converting member, and thus an efficiency of utilizing the light is reduced.